The present invention relates generally to a scroll compressor for use in a refrigerator, an air conditioner, or the like.
One of conventional scroll compressors known in the art is, for example, disclosed in JP-A-2000-161254 and its construction will be described with reference to FIG. 6.
A fixed scroll member 12 and an oscillating scroll member 14 are disposed in a closed vessel 10. The fixed scroll member 12 and the oscillating scroll member 14 have plate-like scroll teeth 16 and 18 having substantially the same shape, respectively. The plate-like scroll teeth 16 and 18 are in gear with each other so as to form a compression chamber 20 which changes in volume relatively between the plate-like scroll teeth 16 and 18.
The fixed scroll member 12 is fixed to a guide frame 22 by a plurality of bolts which are not shown. The guide frame 22 is fixedly attached to the inner wall of the closed vessel 10 by such means as shrink-fitting or welding. The oscillating scroll member 14 and a compliant frame 24 are received in an internal space formed by the fixed scroll member 12 and the guide frame 22. The compliant frame 24 is located under the oscillating scroll member 14 so as to support the oscillating scroll member 14 in the axial direction of the scroll compressor.
At substantially the center portion of a base plate portion 15 of the oscillating scroll member 14, a hollow cylindrical boss portion 26 is formed to extend into the inside of the compliant frame 24. A crank shaft 29 in the upper end portion of a main shaft 28 is rotatably connected to the boss portion 26 through a bearing 27.
The main shaft 28 is driven to rotate by a motor 30. The motor 30 is constituted by a rotor 31 fixed to the main shaft 28, and a stator 32 fixed to the inner wall of the closed vessel 10. The main shaft 28 extends downward so as to be rotatably supported by the compliant frame 24 through first and second bearings 34 and 36 disposed at the upper portion, and by a sub-frame 35 through a third bearing 38 disposed at the lower portion. Further, a main shaft balancer 41 is fixedly attached to the main shaft 28 at the lower side of the crank shaft 29 by shrink-fitting, etc, and an upper balancer 42 and a lower balancer 43 are fixed to the main shaft 28 on the upper and lower surfaces of the rotor 31 respectively. Static balance and dynamic balance of the main shaft 28 are ensured by the three balancers 41, 42 and 43. Incidentally, in FIG. 6, the reference numeral 44 represents glass-sealed terminals for motor power supply purposes.
In addition, an Oldham""s ring 45 is mounted on the compliant frame 24 so as to prevent the oscillating scroll member 14 from rotating on its own axis. The Oldham""s ring 45 has two pairs of claws 46 and 47, and the claws 46 and 47 in each pair have a phase difference of 90 degrees from each other (in FIG. 1, the claws 46 and 47 are shown to have a phase difference of 180 degrees in order to facilitate understanding). The claws 46 are engaged with two Oldham""s guide grooves 48 so that the claws 46 can slide in the grooves 48 reciprocatingly, respectively. The Oldham""s guide grooves 48 are formed substantially in a straight line on a base plate portion 13 of the fixed scroll member 12. The claws 47 are engaged with two Oldham""s guide grooves 49 so that the claws 47 can slide in the grooves 49 reciprocatingly, respectively. The Oldham""s guide grooves 49 are formed substantially in a straight line on the base plate portion 15 of the oscillating scroll member 14 and the Oldham""s guide grooves 49 have a phase difference of 90 degrees with respect to the Oldham""s guide grooves 48, respectively. Thus, the oscillating scroll member 14 driven by the rotation of the crank shaft 29 of the main shaft 28 makes an eccentric turning motion without rotating on its own axis.
The compliant frame 24 has at least two cylindrical surfaces 23 and 25 in its upper and lower outer circumferential portions, respectively. The cylindrical surfaces 23 and 25 engage with cylindrical surfaces 33 and 35 formed in the guide frame 22 so as to be supported in the radial direction of the scroll compressor, respectively. The compliant frame 24 and the guide frame 22 are fitted over each other through upper and lower sealing materials 37 and 39. Thus, a frame space 50 formed between the two members 24 and 22 is sealed off by the sealing materials 37 and 39.
The frame space 50 communicates with a communication passageway 51 provided in the compliant frame 24. The upper end portion of the communication passageway 51 is somewhat expanded in diameter so as to form an opening portion 52. The opening portion 52 is opened to the upper end surface of the compliant frame 24. The upper end surface of the compliant frame 24 serves as a thrust bearing 56. The oscillating scroll member 14 is supported through the thrust bearing 56 slidably in pressure contact with a thrust surface 58. The thrust surface 58 is formed on the lower surface of the base plate portion 15 of the oscillating scroll member 14.
An extraction hole 53 is provided in the base plate portion 15 of the oscillating scroll member 14. A lower end opening portion 54 of the extraction hole 53 is opened to the thrust surface 58 while its upper end opening portion 55 is opened to the compression chamber 20. Further, the thrust-surface-side opening portion 54 of the extraction hole 53 is located so that the circular locus of the opening portion stays in the opening portion 52 of the communication passageway 51 opened to the thrust bearing 56 surface of the compliant frame 24 during the normal operation. Thus, there is no leak to a suction pressure atmosphere space 17 because of the oscillating scroll member 14 and the compliant frame 24 sliding in close contact with each other.
The suction pressure atmosphere space 17 is provided in the outer circumferential portion of the base plate portion 13 of the fixed scroll member 12. A suction pipe 19 for refrigerant gas is press fit into the space 17 through the closed vessel 10. In addition, a discharge port 21 for compressed refrigerant gas is provided in the base plate portion 13. The discharge port 21 communicates with a high pressure chamber 40 formed between the fixed scroll member 12 and the closed vessel 10. The discharge port 21 further communicates with a similar high pressure chamber 62 under the guide frame 22 through a passageway 60. The passageway 60 is composed of a notch groove provided in the outer circumferential portions of the fixed scroll member 12 and the guide frame 22. A discharge pipe 64 is attached to the closed vessel 10 so as to communicate with the high pressure chamber 62.
Lubricating oil 70 such as refrigerating machine oil is stored in the bottom portion of the closed vessel 10. An oil pipe 72 connected with the lower end portion of the main shaft 28 is inserted into the lubricating oil 70. The lubricating oil 70 sucked up through the oil pipe 72 passes through an oil passageway hole 74 extending through the main shaft 28 in its axial direction. Thus, the lubricating oil 70 is directed to the bearing portion 27 of the crank shaft 29 through an opening portion 76 at the upper end of the oil passageway hole. Further, the lubricating oil 70 lubricating the bearing portion 27 fills a space (boss portion space) 78 surrounded by the oscillating scroll member 14 and the compliant frame 24.
FIG. 7 is a partially sectional view showing a pressure regulating mechanism provided in the compliant frame 24.
As shown in FIG. 7, an intermediate pressure regulating valve 80 is incorporated in the compliant frame 24. The intermediate pressure regulating valve 80 uses a spring 81 to close a regulating valve front channel 82. The regulating valve front channel 82 communicates with the boss portion space 78. On the other hand, a regulating valve rear channel 83 communicates with a valve chamber and a base plate outer circumferential portion space, that is, the suction pressure atmosphere space 17 which is low in pressure.
Next, description will be made about the basic operation of this conventional scroll compressor. The low-pressure sucked refrigerant enters the compression chamber 20 from the suction pipe 19. The compression chamber 20 is formed by the plate-like scroll teeth 16 of the fixed scroll member 12 and the plate-like scroll teeth 18 of the oscillating scroll member 14. The plate-like scroll teeth 16 and 18 are in gear with each other. The oscillating scroll member 14 driven by the motor 30 makes an eccentric turning motion while reducing the volume of the compression chamber 20 toward the center portion. By this compression stroke, the sucked refrigerant becomes high in pressure. Thus, the sucked refrigerant is discharged into the closed vessel 10 through the discharge port 21 of the fixed scroll member 12. In addition, on the abovementioned compression stroke, the refrigerant gas of intermediate pressure on the way of compression is directed from the extraction hole 53 of the oscillating scroll member 14 to the frame space 50 through the passageway 60 of the compliant frame 24. Thus, the intermediate pressure atmosphere of the space 50 is maintained. The discharge gas increased in pressure fills the closed vessel 10 with the high pressure atmosphere. The discharge gas is eventually discharged from the discharge pipe 64 to the outside of the compressor.
The lubricating oil 70 in the bottom portion of the closed vessel 10 is directed to the bearing portion 27 of the crank shaft 29 through the oil passageway hole 74 of the main shaft 28 by the high pressure in the closed vessel 10. The lubricating oil attains an intermediate pressure by the throttling action of the bearing portion 27, and it fills the boss portion space 78 surrounded by the oscillating scroll member 14 and the compliant frame 24. Then, the lubricating oil 70 is introduced into the low pressure atmosphere space 17 via the intermediate pressure regulating valve 80 which connects the space 78 and the low pressure atmosphere space 17. Thus, the lubricating oil 70 is sucked into the compression chamber 20 together with the low pressure refrigerant gas. On the compression stroke, the lubricating oil 70 is released into the closed vessel 10 through the discharge port 21 together with the high pressure refrigerant gas. In the closed vessel 10, the lubricating oil 70 is separated from the refrigerant gas, and returned into the bottom portion of the closed vessel again. In addition, the boss portion space 78 is set to maintain a differential pressure defined by the product of the spring constant of the intermediate pressure regulating spring 81 and the sectional area of the regulating valve front channel 82, and to have an intermediate pressure higher than the low pressure atmosphere space 17 by the differential pressure. Thus, the downward force acting on the oscillating scroll member 14 is partially canceled by this intermediate pressure so that the thrust force can be reduced.
The sum of the thrust gas force with which the fixed scroll member 12 and the oscillating scroll member 14 tend to be separated from each other by the compression operation in the axial direction and the force with which the compliant frame 24 and the oscillating scroll member 14 tend to be separated from each other by the intermediate pressure of the boss portion space 78 acts against the compliant frame 24 as a downward force in the drawing.
On the other hand, the sum of the differential pressure between the force tending to separate the compliant frame 24 from the guide frame 22 by the pressure of the frame space 50 to which the refrigerant gas on the way of compression has been directed to form an intermediate pressure atmosphere and the pressure acting on the lower portion of the guide frame 22 which is exposed to the high pressure atmosphere acts as an upward force.
During the steady-state operation, the above-mentioned upward force is set to exceed the downward force. Thus, the engaged upper and lower cylindrical surfaces 23 and 25 of the compliant frame 24 are guided by the cylindrical surfaces 33 and 35 of the guide frame 22. Thus, the compliant frame 24 floats upward. The oscillating scroll member 14 slides on the compliant frame 24 in close contact therewith. Thus, the oscillating scroll member 14 floats in the same manner as the compliant frame 24, and it slides on the fixed scroll member 12 while bringing the plate-like scroll teeth 18 of the oscillating scroll member 14 into contact with the fixed scroll member 12.
On the other hand, the above-mentioned thrust gas force increases during the starting, fluid compression or the like of the scroll compressor. Thus, the oscillating scroll member 14 strongly presses down the compliant frame 24 through the thrust bearing 56. As a result, there is produced a comparatively large clearance between the tooth top and the tooth bottom of the plate-like scroll teeth 18 and 16 of the oscillating scroll member 14 and the fixed scroll member 12. Thus, any abnormal pressure rise in the compression chamber 20 is avoided. This action is called a relief action, and the amount of the produced clearance is called a relief amount.
The relief amount is controlled by a distance of travel until the compliant frame 24 and the guide frame 22 collide with each other.
A part or all of upsetting moment generated in the oscillating scroll member 14 is transmitted to the compliant frame 24 through the thrust bearing 56. On the other hand, a bearing load applied by the first bearing 34 of the main shaft 28, and a resultant of two reactions of the bearing load, that is, a couple produced by a resultant of counterforces produced by the upper and lower cylindrical engaging surfaces (23, 33; 25, 35) of the compliant frame 24 and of the guide frame 22 act on the compliant frame 24 so as to cancel the above-mentioned upsetting moment. Thus, excellent follow-up action stability and relief action stability are ensured during the steady-state operation.
With the conventional scroll compressor, however, there has been a problem at the time of assembling the compliant frame and the guide frame, as follows. In other words, the compliant frame has to be inserted into the guide frame straightly. If the compliant frame is inserted even with a slight inclination, jamming is caused for the compliant frame. Once the compliant frame is brought into such a jamming condition, it is very difficult to further insert the compliant frame or reinsert it from the first. In addition, if the compliant frame is forcibly inserted by hammering with a wooden hammer or the like, the cylindrical engaging surfaces are often damaged or the sealing materials are often damaged or broken. Further, the compliant frame is rotated and adjusted in phase after it has been inserted into the guide frame in the prior art. This operation also causes damage or the like to the sealing materials. In addition, there may arise a mistake such as forgetting to set the sealing materials in place.
The present invention has been made to solve the foregoing problems, and it is an object of the present invention to provide a scroll compressor in which a compliant frame and a guide frame are assembled easily. Particularly, the present invention provides a scroll compressor in which normal assembling of a compliant frame and a guide frame can be made easily.
It is another object of the present invention to provide a scroll compressor in which the compliant frame is adjusted in phase as soon as the compliant frame is inserted.
According to an aspect of the present invention, there is provided a scroll compressor provided in a closed vessel and including: a fixed scroll member attached to a guide frame fixed to the closed vessel; an oscillating scroll member having plate-like scroll teeth engaging with plate-like scroll teeth of the fixed scroll member so as to form a compression chamber between the plate-like scroll teeth of the oscillating scroll member and the plate-like scroll teeth of the fixed scroll member; a compliant frame for supporting the oscillating scroll frame in an axial direction of the scroll compressor in the guide frame; and at least two pairs of cylindrical surfaces, each pair of the cylindrical surfaces being provided in the compliant frame and the guide frame, respectively, one pair of the two pairs being different in diameter from the other pair, thereby supporting the compliant frame in a radial direction of the scroll compressor, and whereby when the compliant frame is inserted into the guide frame, the cylindrical surfaces in pairs are engaged successively in order of increase in diameter.
Thus, the scroll compressor according to the present invention has a feature that the order of places where the compliant frame and guide frame are engaged with each other is defined when the compliant frame is to be inserted into the guide frame. In other words, the first cylindrical surfaces small in diameter are first engaged with each other and the other cylindrical surfaces large in diameter are then engaged with each other in order of increase in diameter. As a result, by the leading action of the first cylindrical surfaces, the insertion of the compliant frame becomes easy, and the compliant frame tends to become difficult to be inclined. Accordingly, it is possible to insert the compliant frame straightly and smoothly without producing any jamming. Thus, it becomes easy to assemble the compliant frame and the guide frame.
According to another aspect of the invention, in the scroll compressor at least two sealing materials are provided for sealing off a frame space formed between the compliant frame and the guide frame so that when the compliant frame is to be inserted into the guide frame, the cylindrical surfaces are engaged first with each other in each pair and then the sealing materials are engaged.
After the two pairs of the cylindrical surfaces have been engaged with each other respectively, the sealing materials are engaged. Accordingly, the sealing materials are engaged while being guided straightly. Thus, it is possible to prevent the sealing materials from being damaged or the like.
According to a further aspect of the invention, in the scroll compressor phase setting means for the compliant frame is provided so that when the compliant frame is to be inserted into the guide frame, the sealing materials are engaged after the compliant frame has been locked in phase with respect to the guide frame by the phase setting means.
By this phase setting means, the phase of the compliant frame, that is, the position of a communication passageway provided in the compliant frame is determined as soon as the compliant frame is inserted. Accordingly, it is not necessary to rotate the compliant frame to position the communication passageway after the compliant frame is inserted. Thus, it is possible to prevent the sealing materials from being damaged or the like.
According to a further aspect of the invention, in the scroll compressor the phase setting means is constituted by at least one pin and one hole, or similar means, so as to prevent the compliant frame from rotating while allowing the compliant frame to move in the axial direction.
A combination of a pin and a hole, a combination of a key and a key groove, or any other means, may be employed as the phase setting means so long as they prevent the compliant frame from rotating but allow the compliant frame to move in the axial direction (vertical movements).
According to a further aspect of the invention, in the scroll compressor all of the sealing materials are mounted on the compliant frame.
Since the presence of the sealing materials can be confirmed easily by visual observation, it is possible to prevent a mistake such as forgetting to set the sealing materials in place.
According to a further aspect of the invention, in the scroll compressor clearances between the compliant frame and the guide frame at the places of engagement of the cylindrical surfaces are smaller than clearances between the compliant frame and the guide frame at the places of engagement of the sealing materials.
According to a further aspect of the invention, in the scroll compressor one of the sealing materials is attached to an insert-direction rear portion of the small-diameter first cylindrical surface, and a seal portion cylindrical surface on which the sealing material is mounted is formed to be slightly smaller than the first cylindrical surface.
According to a further aspect of the invention, in the scroll compressor stated in claim 6, preferably, as defined in claim 7, one of the sealing materials is attached to an insert-direction rear portion of the small-diameter first cylindrical surface, and a seal portion cylindrical surface on which the sealing material is mounted is formed to be slightly smaller than the first cylindrical surface.
The first cylindrical surfaces are first engaged with each other between the compliant frame and the guide frame to play the role of leading when the compliant frame is to be inserted into the guide frame. Accordingly, the fitting tolerance for the guide portion cylindrical surface and the seal portion cylindrical surface in the first cylindrical surface is particularly important to obtain the above-mentioned effect effectively. By forming the seal portion cylindrical surface to be slightly smaller than the guide portion cylindrical surface, the leading function and the normal sealing action of the first sealing material are positively ensured.